Apparatus for cleaning windows

ABSTRACT

A magnetic window cleaning apparatus including a master unit and a slave unit each having angularly disposed panels containing magnetic elements. The units are positioned on opposite sides of a windowpane and are magnetically coupled. The angled panels permit pivoting of a cleaning member mounted on one panel of the slave unit into and out of contact with the windowpane by selective magnetic coupling between the respective panels of the two units due to pivoting of the master unit.

United States Patent 3,492,685 2/1970 Cunon FOREIGN PATENTS 1,545,864 10/1968 France 15/220 A Primary Examiner-Walter A. Scheel Assistant Examiner Leon G. Machlin Attorney-Anderson, Luedeka, Fitch, Even and Tabin ABSTRACT: A magnetic window cleaning apparatus including a master unit and a slave unit each having angularly disposed panels containing magnetic elements. The units are positioned on opposite sides of a window/pane and are magnetically coupled. The angled panels permit pivoting of a cleaning member'mounted on one panel of the slave unit into and out of contact with the windowpane by selective magnetic coupling between the respective panels of the two units due to pivoting of the master unit.

Patented Aug. 24, 1971 3,600,737

I INVENTOR- MZ V/A/ awe:

ATT' Y6.

APPARATUS FOR CLEANING WINDOWS The present invention relates to a window cleaning apparatus. More particularly, it is directed to a window cleaning apparatus comprising a master unit and a slave unit magnetically coupled to the master unit for simultaneously cleaning opposite sides of a windowpane.

Magnetically coupled window cleaning units are known in the prior art and take a variety of forms. Each of these forms involves the use of one or more magnets positioned on opposite sides of the windowpane andcoupled by the respective magnetic fields of the magnets. The master unit which is held by the operator is moved through the desired pattern over the inner surface of the windowpane and the slave unit is caused by the magnetic coupling to follow the master unit throughout the same pattern so that the outside of the window is washed simultaneously with the inside surface. The chief difficulty with the prior art devices has been a failure to provide a compact, easily manageable washing unit while providing sulficient magnetic strength to maintain the slave unit in tracking position with the master unit during the washing operation.

These difficulties are caused in part by the frictional drag of the slave unit on the outer surface of the 'windowpane which often overcomes the magnetic attraction between the master and slave resulting in a magnetic decoupling of the two units causing the slave unit to fall from the surface of the windowpane. I

The problem of providing adequate magnetic force in a small hand manipulatable unit by specific arrangement of discretemagnetic elements for stronger magnetic coupling has been solved by the inventor of the present invention and the solution is set forth in U.S. Pat. No. 3,296,645, entitled Apparatus for Cleaning Windows," issued Jan. 10, 1967. The teachings of the positioning of the magnetic elements set forth in the aforementioned patent are incorporated herein by reference and will not be set forth in detail.

The present invention involves an improved window cleaning apparatus employing the magnetic coupling principles of U.S. Pat. No. 3,296,645 in a novel structure resulting in improved cleaning performance and in increased efficiency.

An object of the present invention is to provide an improved magnetic window cleaning apparatus.

A more specific object of the present invention is to provide a compact, magnetically coupled window cleaning apparatus which can be moved magnetically from an in-use to a retracted position.

A further object of the present invention is to provide an improved magnetic window cleaning apparatus having decreased frictional drag resulting in more effective magnetic coupling of the master and slave units.

Still a further object of the present invention is to provide a magnetic window cleaning apparatus capable of disengaging a window cleaning member on the slave unit from the windowpane by manipulating the master unit to cause selective coupling of different portions of the slave unit.

These and other objects and advantages of the present invention will become obvious from the following description and the associated drawings in which:

FIG. 1 is a perspective view of the apparatus of the present invention positioned on opposite sides of a windowpane;

FIG. 2 is a sectional view of the apparatus of the present invention taken along line 2-2 of FIG. 1;

FIG. 3 is an exploded perspective view showing the master and slave units spaced away from each other and illustrating an arrangement for the magnetic elements.

Briefly, FIG. 1 illustrates an embodiment of the apparatus of the present invention including a master unit 10, a slave unit 12, and a window cleaning member positioned on the slave unit and illustrated in the form of a squeegee 14. The units are positioned on either side of a windowpane l6 and are magnetically coupled so that the slave unit is held in substantial alignment with the master unit 10. A cord 18 is attached to the slave unit so that the slave unit will not be damaged if it accidentally becomes uncoupled. The cord may, of course, be used in conjunction with a reel (not illustrated) attached to the unit or units to take up the slack. As can best be seen from FIG. 2 contact with the surface of the windowpane on either side is provided by small bearing areas 20 so that the entire surface of the unit does not cause frictional drag on the surface of the windowpane.

Both units are made up of a pair of angularly disposed, flat, connected panels and each panel includes magnetic elements having poles oriented perpendicular to the respective panel face. When the units are positioned on a windowpane two of the panels are parallel to the window and magnetically coupled while the remaining two panels are inclined away from the window.

Pivoting the master unit so that the opposite panel is parallel to the window creates a new magnetic couple which causes a corresponding pivotal movement of the slave unit resulting in engagement or disengagement of the cleaning member and the window. This selective coupling of the respective panels permitting engagement and disengagement of the cleaning member on the slave unit is one of the novel features of the present invention. 7

Referring specifically to FIG. 3 it can be seen that the flat panels 22 and 24 of the master unit are rectangular in shape and have a thickness which is small in comparison to their other dimensions. The panels 22 and 24 are joined along one common edge and are disposed at an angle to each other which, for purposes of discussion, will be termed 0, describing the included angle, less than. between the backs of the panels.

The master unit 10 is further provided with an outer sheet 26 which forms part of the frame for the master unit and is employed as a backwall for both panels 22 and 24 on the side away from the window. The outer sheet 26 is bent on the line joining the panels, and preferably is made of a magnetic material. The sheet 26 also forms a border 28 aroundthe edges of the two panels providing a peripheral frame around the entire master unit. The result is a boxlike configuration open at one side and bent at its midportion. The frame acts as a receptacle for the magnetic elements 32 which are positioned in each of the panels 22 and 24 as will be described hereinafter.

It is preferred as stated above that the frame be made from a magnetic material since it not only acts as the structural member for the master unit but also provides a path for the magnetic flux from the magnetic elements in the panels so as to prevent losses and increase the magnetic coupling effect of the unit.

The magnetic elements 32, in the illustrated embodiment, comprise independent pieces of magnetized material either metal or ceramic having pole faces oriented parallel to the faces of the respective panels in which they are inserted. The magnetic elements are generally cube shaped and are positioned in rows within the panels in a rectangular array. In the embodiment shown in FIG. 3 the two such rows of magnetic elements are positioned within the frame for each panel 22 and 24. It can also be seen from FIG. 3 that adjacent magnetic elements in each panel are of opposite polarity to form a checkerboard pattern. The reason for forming the checkerboard pattern is to increase the coupling effect so that the slave unit will track the master unit faithfully. The elements are spaced slightly to reduce leakage flux between elements. The spaces are filled with nonmagnetic material such as resin.

The technical explanation for the added coupling effect caused by the particular positioning of the magnetic element and enhanced by the magnetizable material of the frame is clearly set forth in U.S. Pat. No. 3,296,645, mentioned earlier and will not be repeated herein except to say that the arrangement provides increased lateral or tracking forces between the units over that of a single magnet. It should be understood,

- however, that a single sheet of material may be employed with magnetized regions which are equivalent to the illustrated discrete magnetic elements.

The bearing members 20 mentioned above are positioned on the frame of the master unit and, in the illustrated embodiment, are located at each end of the line joining the two panels 22 and 24 to provide a pivot point for the unit and at the center of the ends of the frame. As a result, for each coupled position of the master unit, three bearing points of contact will be maintained, namely, the two bearing points at the line joining the panels and the bearing point on the opposite side of the respective panel which is positioned parallel to the windowane.

p The bearing points may take any suitable form although it has been found that small diameter ball bearings either steel or nylon rollably mounted in the frame provide particularly good results in overcoming friction on the windowpane. It is also possible to use small fixed projections of material having a low coefficient of friction in place of the rolling type bearings although some problems are encountered with chatter of the unit if the window surface is extremely dirty.

The slave unit 12 is constructed similarly to the master unit and includes a pair of generally flat panels 34 and 36 also joined along a common edge and angularly disposed with respect to each other. For purposes of discussion the included angle, less than 180, between the panels on the slaveunit will be termed 1 The slave unit is also provided with a frame in the form of a sheet of material 38 which also surrounds the periphery and the back of both panels 34 and 36. This sheet 38 performs the same function as the sheet 26 in the case of the master unit. Bearing points 20 similar to those in the master unit are also provided at the same locations on the slave unit. The slave unit in the illustrated embodiment includesa bracket 42 affixed to the outside of the panel 34 on the back of sheet 38 by suitable means such as welding or soldering. The bracket is in form of a shallow U-shape and provides a narrow opening or slot between the bight portion of the U-shape which is flat and the outer surface of the panel 34. This opening or slot receives a spring clip 44 on the end of a handle 46 which in turn is attached to the cleaning member. The cleaning member is thus held firmly but removably in the bracket and the handle extends along the back of the panel and parallel thereto.

The fixture at the end of the cleaning member may be a cloth or sponge 48 as illustrated in FIG. 3 as well as the squeegee 14 illustrated in FIG. 2. Because of the removable type mounting provided by the bracket it is possible to interchange the sponge and the squeegee for successive cleaning operations as will be described hereinafter.

As can be seen from FIG. 2 only one panel of each unit, master and slave, is magnetically coupled and parallel to the corresponding panel of the opposite unit at any one time due to the angled disposition of the panels. The remaining two panels extend on an angle away from each other and from the windowpane. The window cleaning member is attached to the side away from the windowpane of one panel of the slave unit and extends beyond the panel to contact the window when the slave unit is in the proper position. The master unit and the slave unit are positioned on either side of the windowpane so that the magnetic elements in two of their respective panels are magnetically coupled with each other. In the solid line position illustrated in FIG. 2 the upper panels 22 and 24 which are of essentially the same size and shape are positioned directly across from and parallel to each other and are magnetically coupled. In order to accomplish this the magnetic elements are situated so that the respective north and south poles are oriented in the same direction for corresponding magnetic elements in the checkerboard pattern on either side of the window, that is a south pole of the slave unit is positioned directly across from and facing a north pole of the master unit so that they attract.

As mentioned earlier one novel feature of the present invention resides in the provision of the two units, master and slave, each having a pair of panels angularly disposed with respect to each other so as to effect disengagement of the cleaning member from the slave side of the windowpane by manipulation of the master unit on the inside of the window. As can be seen from FIG. 2 the included angle 0 between the panels 22 and 24 of the master unit 10 is less than the included angle I between the panels 34 and 36 of the slave unit 12. Consequently, the spacing of the magnets in the panel 24 from the surface of the windowpane is greater than the spacing of the corresponding magnets of the panel 36 when the upper panels 22 and 34 are magnetically coupled and the cleaning member is engaging the windowpane.

If the operator pivots the master unit 10 about the line joining the panels 22 and 24 on the bearings 20 so that the lower panel 24 is disposed parallel to the windowpane the magnetic attraction in that position will be greater between the panel 24 and 36 than between the panels 22 and 34 due to the lesser spacing between the panels 24 and 36 in this position. The foregoing is true for magnets of equal strength because magnetic attraction is a function of the distance between the attracting and the attracted body, and specifically the magnetic force varies approximately inversely with the square of the linear distance between the bodies. Therefore by positioning a panel 24 closer to the panel 36 than the panel 22 is'to the panel 34, the magnetic attraction between the two lower panels will be strong enough to cause uncoupling of the upper panels and the pivoting of the slave unit about its line joining the two panels 34 and 36 resulting in a coupling of the lower panels of the respective units parallel to the windowpane and causing disengagement of the cleaning unit on the top panel 34 of the slave unit from the window. If the included angles 0 and Q were not of a different size and if the angle 0 were not less than the angle 1 so that the master unit moved through a greater arc in changing from one panel to another, pivoting of the slave unit would not reliably be attained because there would be no breaking of the existing coupling force between the panels parallel to the windowpane. This can be illustrated by envisioning the slave unit and the master unit in FIG. 2 and pivoting it to the dash line position shown. In that position the upper panel 34 of the slave unit will still be closer to the upper panel 22 of the master unit than will the lower panels of the respective units resulting in the coupling remaining stronger on the upper panel and releasing of the slave unit will cause the slave unit to pivot back to the solid line position shown in FIG. 2.

The operation of the improved apparatus of the present invention is simple. In a typical application the operator inserts a wet sponge into the bracket on the back of the slave unit and places the slave unit outside the window with the upper panel 34 parallel to the glass. The master unit is then placed with the panel 22 in register with the slave unit on the inside of the window to form the magneticcouple. The master unit is then move over the entire window surface so that the slave unit washes the outside of the window. This movement may include turning the unit sideways or to an inverted position. With the rectangular array of magnetic members, the slave unit will duplicate the movements of the master unit exactly.

After the entire window is wetted, the units are moved to the retracted position by pivoting the master unit to the lower panel 24 and forming a new magnetic couple as described earlier. The sponge is then replaced with the squeegee l4 and the units are moved to the top of the windowpane and pivoted to the in-use position. After each wiping passage across the window, the units are moved to the retracted position until properly located for the subsequent wiping passage. Consequently the squeegee operation is quite similar to that of a manual operation.

Other variations and embodiments are clearly within the scope of the present invention. For example it is evident that a similar bracket and cleaning element shown in phantom in FIG. 3, might be employed on the master unit to wash both sides of the window simultaneously. Another embodiment includes the mounting of the sponge on one panel of either unit and the squeegee on the other panel of the same unit. The advantage of this embodiment is that when the sponge is retracted the squeegee is already in place thus avoiding the time loss of changing from one to the other in the embodiment illustrated. Still another embodiment might utilize mechanical means for disposing the slave unit and its associated cleaning means in proper position on the outside of the window to be cleaned to thereby enable the window cleaning apparatus of the present invention to be used on permanently closed windows or window panels.

Various of the features of the present invention are set forth in the following claims.

What I claim is:

1. A magnetic window cleaning apparatus comprising a master unit and a slave unit adapted to be disposed on opposite sides of a windowpane in magnetically coupled relationship for remote-control cleaning of one surface of the windowpane, each of said units comprising a frame having two panels joined along one of their respective edges and angularly disposed with respect to each other so that one of said panels is disposed at an angle to the windowpane when the other of said panels is disposed parallel to the windowpane, the included angle between the panels of said master unit being less than the included angle between the panels of said slave unit, a

magnetic element disposed in each panel of each of said units,

said magnetic elements being magnetized perpendicular to the plane of the panel in which they are disposed, and being so arranged as to be opposite a magnetic element of opposite polarity in the complementary panel of the other unit so that opposing magnetic elements may be magnetically coupled, and window cleaning means attached to said slave unit, whereby said cleaning means on said slave unit is adapted to be caused to selectively engage and disengage said windowpane in response to the engagement of the corresponding panel of the master unit with the opposite side of said windowpane upon pivotal movement of said master unit.

2. An apparatus as set forth in claim 1 wherein each of said panels further comprises a plurality of magnetic elements arranged so that alternating ones of said elements are of alternating polarity in each of said panels.

3. An apparatus as set forth in claim 2 wherein each of said frames further comprises an angled sheet of magnetizable material upon one side of which said magnetic elements are mounted so that said frame acts as a bridge for magnetic flux between adjacent magnetic elements of said units.

4. An apparatus as set forth in claim 1 wherein said frames further comprise bearings disposed on each panel to prevent direct engagement of the panel surface with said windowpane whereby the slave unit more readily follows the movement of said master unit.

5. An apparatus as set forth in claim 2 wherein said magnetic elements are rectangular in shape and are disposed in a spaced rectangular array in each of said panels with a magnetically insulative medium interposed between their respective edges.

6. An apparatus as set forth in claim 1 wherein said cleaning means is mounted on and extends parallel to one of said panels of said slave unit in a direction generally perpendicular to the line joining the panels of said slave unit whereby the selective engagement of said panels with said windowpane selectively engages and disengages said cleaning means from said windowpane.

7. An apparatus as set forth in claim 6 wherein said cleaning means is removably mounted on said slave unit so that multiple cleaning means may be employed sequentially on said slave unit. 

1. A magnetic window cleaning apparatus comprising a master unit and a slave unit adapted to be disposed on opposite sides of a windowpane in magnetically coupled relationship for remotecontrol cleaning of one surface of the windowpane, each of said units comprising a frame having two panels joined along one of their respective edges and angularly disposed with respect to each other so that one of said panels is disposed at an angle to the windowpane when the other of said panels is disposed parallel to the windowpane, the included angle between the panels of said master unit being less than the included angle between the panels of said slave unit, a magnetic element disposed in each panel of each of said units, said magnetic elements being magnetized perpendicular to the plane of the panel in which they are disposed, and being so arranged as to be opposite a magnetic element of opposite polarity in the complementary panel of the other unit so that opposing magnetic elements may be magnetically coupled, and window cleaning means attached to said slave unit, whereby said cleaning means on said slave unit is adapted to be caused to selectively engage and disengage said windowpane in response to the engagement of the corresponding panel of the master unit with the opposite side of said windowpane upon pivotal movement of said master unit.
 2. An apparatus as set forth in claim 1 wherein each of said panels further comprises a plurality of magnetic elements arranged so that alternating ones of said elements are of alternating polarity in each of said panels.
 3. An apparatus as set forth in claim 2 wherein each of said frames further comprises an angled sheet of magnetizable material upon one side of which said magnetic elements are mounted so that said frame acts as a bridge for magnetic flux between adjacent magnetic elements of said units.
 4. An apparatus as set forth in claim 1 wherein said frames further comprise bearings disposed on each panel to prevent direct engagement of the panel surface with said windowpane whereby the slave unit more readily follows the movement of said master unit.
 5. An apparatus as set forth in claim 2 wherein said magnetic elements are rectangular in shape and are disposed in a spaced rectangular array in each of said panels with a magnetically insulative medium interposed between their respective edges.
 6. An apparatus as set forth in claim 1 wherein said cleaning means is mounted on and extends parallel to one of said panels of said slave unit in a direction generally perpendicular to the line joining the panels of said slave unit whereby the selective engagement of said panels with said windowpane selectively engages and disengages said cleaning means from said windowpane.
 7. An apparatus as set forth in claim 6 wherein said cleaning means is removably mounted on said slave unit so that multiple cleaning means may be employed sequentially on said slave unit. 